ATP Flashcards
What is ATP?
Adenosine Triphosphate
The universal energy carrier in all living cells.
Where is ATP produced?
ATP is synthesised on the internal membranes of mitochondria and chloroplasts.
Describe how ATP is synthesised.
- Involves ATP synthase, an enzyme found embedded in cellular membranes
- ATP synthase phosphorylates ADP to form ATP as protons flow through it
Compare the flow of protons across the mitochondrial and chloroplast membranes.
Mitochondrial membrane: H+ flow from the intermembrane
space into the matrix, across the inner membrane.
Chloroplast membrane: H+ flows from the thylakoid space into the stroma, across the thylakoid membrane.
Define chemiosmosis
The synthesis of ATP through the movement of protons down their electrochemical gradient across a semi-permeable membrane, catalysed by ATP synthase.
How is the proton gradient maintained during chemiosmosis?
Potential energy associated with excited electrons is coupled to the active transport of H* across the membrane by proton
pumps.
What is the electron transport chain?
A series of electron carrier proteins that transfer electrons in a chain of oxidation-reduction reactions, releasing
energy.
How can dehydrogenase activity be
investigated?
Investigated using artificial hydrogen acceptors such as DCPIP, methylene blue and tetrazolium compounds.
What colour change is observed when DCPIP is reduced?
Dark blue to colourless
What colour change is observed when methylene blue is reduced?
Dark blue to colourless
